1. The present invention relates to testing apparatus particularly adapted for use with side frames of trucks for railway cars.
2. Prior Art
In the prior art the desirability of testing side frames of railroad cars has long been known. The "Symington" Side Frame Testing Machine has been used for many years, and comprises a very large complex machine that does in fact include loadings in several directions including vertical, transverse, center twist, longitudinal, end twist, center impact and end impact. The loads can be cycled as they are applied and the side frames are primarily loaded in the Symington machine through complex spring and linkage arrangements. Further, the force applying mechanisms are made so that there is a substantial amount of cross talk between the individual forces being applied which makes it hard to control the tests accurately.
Another type of fatigue tester for railway side frames is made by the American Steel Foundries Company.
In the patented art, U.S. Pat. No. 3,718,040 illustrates a Method and Apparatus For Evaluating Railroad Track Structure And Car Performance utilizing the axles and wheels of the railroad car mounted in the side frames that are illustrated in that patent. The patent deals with measuring the actual forces during use, as a means of disclosing track condition changes between different runs with the same side frame assembly.
U.S. Pat. No. 3,257,844 illustrates an apparatus for testing the sills of cushion cars wherein the entire railroad car is loaded in a desired manner, and U.S. Pat. No. 2,431,295 also illustrates a device for loading an entire car relative to rails for testing various components of a railway car.
U.S. Pat. No. 3,135,106 shows a Static-Dynamic Fatigue-Creep Testing Apparatus that utilizes a type of a C shaped spring for loading in one direction. U.S. Pat. No. 3,713,330 also shows a type of device for loading an axle in three different axes, utilizing bell crank arrangements for keeping the unit compact, and also includes servo controlled cylinders for loading.
Additional patents which show fatigue or other testing for vehicle components include U.S. Pat. No. 3,229,510 which tests apparatus for ball screws and ball driven actuators; U.S. Pat. No. 3,581,560 which provides a stationary test stand for vehicles; and U.S. Pat. No. 3,555,893 which simulates lateral and steering forces on an automobile frame.